A broach of this I have made in another thread, and rather than comment further there I thought I would create a topic. In 2008 on another message board on the subject of pattern mimicry I brought this up, and nobody commented. I pigeon pecked on my first computer thoughts I only wrote in spiral note pads before. But the demographic was different, and once I came here, I didnt want to go on there anymore.

A little later I found out there was an actual theory about what I believed questioned the settled on models of Mimicry. At least in some (many? most?) snakes.

Motion Dazzle Camouflage.

To start off I cant help but look at a snake as a whole, and see an animal with a paradoxical bauplan. Limited and vulnerable on one hand - adept and terrain capable on the other. Snakes are found in practically all biome types, venomous and non vens.

What would more likely be useful as a survival tactic in the the most circumstances - with the most predators - outline/contrast distortion in motion or having a similiar contrast pattern to a venomous species that in some cases doesnt even occur in the non ven's range?

There are more banded non venomous species than banded venomous species, and all snakes venomous and non venomous, are prey.

That there are more banded non vens than vens it is a given that there are more non venomous species globally, and that a banded pattern isnt a warning sign but has more to do with predator types than the venomous or non venomous status of the species.

Like, the bandedness is proportionately distributed and its function isnt a warning but a feature of visual disorganization for predators. Also encountered in subterrain cover, moving in, segmented in exposure. We have all seen snakes in these situ and how even plainly colored ones appear to be moving faster than they actually are, but what do non primates see?

I am not intimately familiar with the research surrounding snake mimicry and snake patterns, but one of the hypotheses of banding is a flicker effect when they're moving. It makes it difficult for predators to track.

In relation to mimicry of venomous species such as in coral snake when the model is no longer sympatric, there has been some work done on those. Some folks found that the coral snakes mimics have evolved to be more precise mimics after model extirpation. The idea is that even without the models, relatively few predator generations happened so mimics can play off of cultural learning in the predators to continue to use the benefit of warning coloration.

It is possible that conspicuous banded signals easily evolved from cryptic signals because it still plays on the flicker effect.

Thanks for your response, your excellent information gave me some temperance in thought.

I admit I am vigilant in a disdain towards anthropocentric projection in the perceptions of other animals. I 'think' that most other animals respond more casually to snakes than we do and how it may bleed its way into some canonized scientific statements. Esp in the past. But I dont want that to get in the way of learning. You peeped me to some stuff I need to look into.

On another kind of related note I was checking out some material on Vermicella annulata recently on my day off, they are a fascinating snake and I came across some better images than before and was struck by the gestalt, how much it reminded me of a Coral Snake.

I question whether the bright colors of some aposematic species are more representative of a shared ancestral trait that hasn't evolved to be otherwise, given the fact that so many of these aposematically colored species are either fossorial or otherwise very secretive. What good do bright colors do when you're underground or nocturnal?

Nocturnal and diurnal activity patterns can be plastic with many snakes, including banded species like Coral Snakes and Zonata.

Cryptic life has great benefits of protection and energy expenditure for a snake, but there is plenty of evidence in sightings alone that bear witness that discreet to overt (on crawl) surfacing for resources or at impetus is not rare.

The phylogeny aspects perhaps can be explored by someone It really is an expansive mosaic of a topic. Not just about the snakes but the predators and their features of vision and responses.

I question whether the bright colors of some aposematic species are more representative of a shared ancestral trait that hasn't evolved to be otherwise, given the fact that so many of these aposematically colored species are either fossorial or otherwise very secretive. What good do bright colors do when you're underground or nocturnal?

That is a good question, and there are a lot of nocturnal animals that are pretty colorful (Red-Eyed Tree Frogs, for example). As a color biologist, it drives me nuts. My best guess is that predators encounter these during the day while foraging. And encounter rate doesn't have to be super high to elicit avoidance. I've done research on aposematic colors and learning in birds, and it can take just one encounter to elicit avoidance. So, encounter rate doesn't need to be super high.

I question whether the bright colors of some aposematic species are more representative of a shared ancestral trait that hasn't evolved to be otherwise, given the fact that so many of these aposematically colored species are either fossorial or otherwise very secretive. What good do bright colors do when you're underground or nocturnal?

MonarchzMan wrote:

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That is a good question, and there are a lot of nocturnal animals that are pretty colorful (Red-Eyed Tree Frogs, for example). As a color biologist, it drives me nuts. My best guess is that predators encounter these during the day while foraging. And encounter rate doesn't have to be super high to elicit avoidance. I've done research on aposematic colors and learning in birds, and it can take just one encounter to elicit avoidance. So, encounter rate doesn't need to be super high.

Really interesting thoughts and subject.

As it applies to tricolors, shared ancestral traits seem likely in the colubrids and it seems DNA systematics would or will show this???

Help an old guy whose formal zoological training was in the Middle Ages. Do I remember a biological principal that effectively said that once an evolved advantage (or even appendage) is acquired, if it no longer is necessary, it doesn’t necessarily disappear; it may become vestigial, but if the evolved trait doesn’t help or hurt, it remains???

Please correct me if I'm wrong, but don’t most large, mammalian predators, like canids, have only marginal red recognition in daylight, and virtually no red recognition at night.

Even with us humans, red is pretty lean in low light. I guess seeing red in the day time is more important to us, and our berry eating brethren species.

A warning red in daylight would be a real advantage against the more serious avian predators . Could this even be very important to fossorial animals that are flooded out periodically????

This is why I need convincing, something is amiss to me, the vast spectrum of predators and diversity of their visual systems. Is avoidance more theoretical than recorded?

Brightly marked herps are also common. How to know, with Red Eyed Tree Frogs for example, that their marks are for warning or actually more for recognition/reproduction. I have watched herps of many types become animated at strategically visual angles and distances from each other during courtship or territorial events.

I think one difficulty you are having here is to think that traits must encode for one function alone (e.g, Red=X ∨ Red=Y). It is more precise to say that traits, such as color, may be encoding a variety of functions and that you/we may be assigning a category to that. So there could be any number of causal explanations that are plausible: warning, shared ancestry, "green beard", or some other justifiable relationship. I think there is a conceptual bias we, as observers of the natural world, have towards giving singular explanations. This is not to say all interpretations are equally valid or acceptable. Rather, if this is enough justification we may find ample evidence to support individual claims. In the case of colors, there appears to be sufficient evidence to suggest that red is a warning coloration so we may assent to that claim. Other pieces of evidence, such as the phylogeny, seem plausible for certain species of snakes, particularly fossorial ones.

Disclaimer: I'm no biologist, just a philosopher who studies this stuff. :p

I totally agree with the tendency to singularize and am conscious not to entertain such, have actually written about it elsewhere on the forum myself which is why i said "more"

When something is good, its 'good' in many ways. But the species that are highlighted for aposemetic markings, and the venomous themselves are such frequent prey items that I am asking these questions.

Im on a really sticky, janky PC at work and my tightness in response is mechanical.

This is roughly what I have the tendency to think and need more information about because I am really interested and will find no other format or group of people who will be able to provide it in one spectral, communicative space :

That the understanding of the visual systems of animals are only recently enabled by technologies, and that although color reception and neural schematics may vary by animal group, contrast in motion would have an effect 'universally' with species vision, variance a given, to achieve delay, confusion, bipass.

That venomous snakes and non venomous snakes are more highly demarcated in our experiences than in other animal predators.

That venom in snakes evolved as primarily a food dispatch acquisition.

That the badges, lateral marks, accentuated eyes & supraorbital outlines and other augmented morphologies in herps are intra species recognition cues, and that they do not have much of an affect on poikilothermic predators ie snakes, fishes. (or mammals)

Birds as mentioned before are extremely well sighted and savvy and capable of building on experiences. Predatory birds will recognize a potential danger but are adept at surpassing it and will readily kill and eat venomous snakes. But would avoid a poisonous insect, anuran or plant

It is mentally limiting to have the fear of changing one's mind. I dont have that fear.

Okay Gene - I have read the study just now and could almost feel my brain tissue move.. At least in regards to birds which I think of as epitome snake predators.

A convincing factor that was strong for me was that the models were non-moving.

Does any one have any input about any of the other things I have posted? I posted in earnest my raw thoughts and have gone out on a limb - can any one else join me out here on the tangentials I have attempted to describe? Either with more data, on other predator types or with their own thoughts on the items?

The text I am looking at is Savage (2002) "The Amphibians and Reptiles of Costa Rica." I understand some things, particularly, taxonomy have changed in the subsequent 15 years, but much of the information in the book is relevant to this.

When introducing micrurus (p. 704-705), he notes several studies to argue for the anti-predatory nature of their behavior.

These strongly suggest a correlation between avian anti-predatory display and the coloration. His discussion is quite interesting in the text, too, of the studies Smith (1975 & 1977) performs).

My research has focused on what "fitness" means in evolutionary theory. I think that is quite a bit far removed from this topic to go into much detail. I do think biologists are too quick to make a causal story between a trait and a singular story about that trait. Traits, you might say, do not exist in a vacuum, but are encoded alongside a host of other genetic conditions. I hope at the very least the studies linked to here and by others can help your current problem.

I'm not convinced that tricolored mimicry is entirely due to predatory avoidance. Kelly's assertion of "motion dazzle" camouflage makes sense when encountering these animals during the day. When stumbling across a fast moving coral snake or milk snake in the day, it is awfully hard to visually track them, especially if they're in grass or high-contrast vegetation.

However, these are primarily nocturnal snakes, and I believe their nocturnal behavior and hunting habits led to the evolution of this pattern, more so than predatory avoidance. The red spectrum is the most difficult wavelength of light to see at night. Combined with pattern breaking black and yellow/white makes these snakes very difficult to see at night for predators, unless they are moving out in the open.

While it is a singular data point, I have personally come across a great horned owl in the road attempting to predate upon a Mexican milk snake, in an area which is equally abundant with Texas coral snakes. While well camouflaged in the grass, both are easy to observe moving across the road.And I say the owl was attempting to predate, as the milk snake had managed to wrap itself twice around the neck of the owl, and had begun to suffocate it. Upon encounter, the owl was unable to fly and was flopping helplessly in the road. The owl was freed, and flew away unharmed, and the milk snake later succumbed to its injuries.

I personally think a lot of 'mimicry' cases in herps are false. Color and pattern similarities arose by convergence or some other ecological method instead.

umop apisdn wrote:

I question whether the bright colors of some aposematic species are more representative of a shared ancestral trait that hasn't evolved to be otherwise, given the fact that so many of these aposematically colored species are either fossorial or otherwise very secretive. What good do bright colors do when you're underground or nocturnal?

Ever see a snake with bright colors move at night? They ain't so bright, they blend in - esp. crawling on leaf litter (or through).

Furthermore, while I dismiss the majority of claims that Scarlet Kingsnakes mimic Coral Snakes, I do recognize that some tropical species likely do 'mimic' (via some method that appears to be similar) each other and our Scarlet Kingsnake and Coral Snakes still possess those coloration and pattern traits (to some extent) as they still benefit (or are of no consequence) to them.

pyty the owl was assisted, i am especially interested in these events where raptors are strangled by their prey, it is very abnormal in nature for predators to attempt to kill dangerous prey unless near starvation, yet we fairly often see or hear of buteos (red tails & red shouldered) near death w/ an elaphae or pit wrapped around their necks.I posted a fascinating acct of a sonoran corale a few years ago that had been killed but abandoned by a predator & thus likely had envenomated it, i really need to publish that one, one of these daze ...Another time i watched a coyote nonchalantly attack a large pit w/o any concern for its rattlesnake mimickry & wrote in my writeup; what good did the crote-mimickry defense make, why was it selected for ? When does it ever dissuade an attack ?Join the ranks of those of us who are mystified by it all, clearly; elaps regalis when displaying its red ventral coil is asserting its venomous state in a highly ritualized behavior, but do they actually bite? I only know of one instance where this did occur ... great area for experimental work, if the experiment is done w/ due diligence to "methods"Consider how a lateralis, particularly in brush can move w/ great alacrity, yet appear immobile, how a mtn king can move & become suddenly invisible!Does the hognose antics dissuade anything ophiphagous? When it "possums up", what predator walks away ?

Good field biology always develops better questions, if few definitive answers ... rxr ... i cant believe its so damn hard to get a fricken jpg to lode ... eerr ...

I'm not convinced that tricolored mimicry is entirely due to predatory avoidance. Kelly's assertion of "motion dazzle" camouflage makes sense when encountering these animals during the day. When stumbling across a fast moving coral snake or milk snake in the day, it is awfully hard to visually track them, especially if they're in grass or high-contrast vegetation.

However, these are primarily nocturnal snakes, and I believe their nocturnal behavior and hunting habits led to the evolution of this pattern, more so than predatory avoidance. The red spectrum is the most difficult wavelength of light to see at night. Combined with pattern breaking black and yellow/white makes these snakes very difficult to see at night for predators, unless they are moving out in the open.

While it is a singular data point, I have personally come across a great horned owl in the road attempting to predate upon a Mexican milk snake, in an area which is equally abundant with Texas coral snakes. While well camouflaged in the grass, both are easy to observe moving across the road.And I say the owl was attempting to predate, as the milk snake had managed to wrap itself twice around the neck of the owl, and had begun to suffocate it. Upon encounter, the owl was unable to fly and was flopping helplessly in the road. The owl was freed, and flew away unharmed, and the milk snake later succumbed to its injuries.

Why could it not be both? And in all likelihood, it is both. If avoiding detection was the goal, then why not just be black? Coral snakes may play on both the fact that red is difficult to see at night, but also that it actually is a highly effective signal during the day. It's a win-win for the coral snakes. During the day, they can be protected by bright colors conveying venom to predators that see in color quite well, and at night, utilize the fact that red does not transmit well, and thus be protected from predators that do not see color well.

There is a bit of evidence that these signals do not serve a single purpose. For example, the orange Strawberry Poison Frogs (Oophaga pumilio) have been shown to use the orange coloration as a signal both for aposematic purposes and for sexual selection.

To those confused as to whether or not nonvenomous look-alikes are actually mimicking coral snakes, combine the paper I shared earlier (giving strong evidence for the power of coral snake aposematism, even working to a degree in non-visual predators) with the biogeography of Pliocercus elapoides. That snake is as strong a proof of Batesian mimicry as you can find, the proof of concept for the larger theory that would make milk snakes, scarlet snakes, etc., mimics of coral snakes.

I especially like the shift from ringed young to solid black adults in L.t.gaigeae, makes sense when you consider the risk of predation likely goes down as these snakes mature into large adults and require less protection and more thermal regulation ability at the high elevations they inhabit.

given the fact that so many of these aposematically colored species are either fossorial or otherwise very secretive. What good do bright colors do when you're underground or nocturnal?

Nature is cryptic. For snakes its always hide first. Buy most cant always hide. Coral snakes, kingsnakes, tri colored hognose all these types of snakes spend some time crawling exposed in daylight. Mornings, early evenings, overcast days. They are active hunters that don't stay buried their whole lives. When species like corals are out from under cover its because they are actively moving from one place to another. This is when they are at their greatest risk. So bright warning colors seem to make sense. It would also make sense for snakes that share similar habits to mimic this defense.

I don't know what red looks like to an Owl at night. I think a larger threat in many cases for tri color snakes are animals that root around looking for food at dusk or early morning , raccoons or opossums (immune to all snake venom, except coral snake venom).For these animals that possess a limited herpetological knowledge .I think turning up any brightly colored snake might be a deterrent. The color scheme might serve one purpose and the pattern could serve another. A blending of two common strategies. Obviously whatever the idea it is incredibly successful.

I don't know what red looks like to an Owl at night. I think a larger threat in many cases for tri color snakes are animals that root around looking for food at dusk or early morning , raccoons or opossums (immune to all snake venom, except coral snake venom).For these animals that possess a limited herpetological knowledge .I think turning up any brightly colored snake might be a deterrent. The color scheme might serve one purpose and the pattern could serve another. A blending of two common strategies. Obviously whatever the idea it is incredibly successful.

Your point is taken and, I would argue, correct, though your example is not. Mammals, by and large, have very poor color vision, if at all. We are pretty unusual for mammals in being able to see color. It's thought we evolved color vision to be able to distinguish ripe fruits. Nocturnal mammals (I'd guess owls, too) generally have no need to see color, so they have greater variety/density of rods (light sensing photoreceptors).

That said, from mammal vision perspective, the tricolor pattern would probably look something like white and black banding. A high contrast signal like that may act like an aposematic signal.

The color, however, is almost certainly geared for color vision predators, which are likely primarily composed of birds.

I remember reading that mammals take in visual information in a different format and rapidity, where a flickering of image is already intrinsic to perception. Bandedness in snakes and its flicker contrast in motion would be an enhancement feature perhaps. Canids I think were the example given.

I find it all very fascinating and it reaches into many focus points. I appreciate every post shared and all of the links and experiences of all you guys helping me understand this topic and become interested in it even more.

I remember reading that mammals take in visual information in a different format and rapidity, where a flickering of image is already intrinsic to perception. Bandedness in snakes and its flicker contrast in motion would be an enhancement feature perhaps. Canids I think were the example given.

I find it all very fascinating and it reaches into many focus points. I appreciate every post shared and all of the links and experiences of all you guys helping me understand this topic and become interested in it even more.

-Kelly

Visual acuity I think is pretty variable among species. I would have to read more on the literature about it, but a friend of mine has done some stuff with visual acuity in animals, and I think I recall seeing that it's very variable among species. I'm not sure there are broad taxon-specific patterns. But I'm not certain there as it's not my area of expertise.

Nocturnal mammals (I'd guess owls, too) generally have no need to see color, so they have greater variety/density of rods (light sensing photoreceptors).

None of the animals I mentioned hunt solely in complete darkness. Just like the snakes they are active during periods when there is enough available light to distinguish patterns and color. It doesn't matter if an animal sees red, black and yellow banding as bright colors. They can still distinguish the differences in appearance. The colors at the vey least must present a difference in pattern and shading. Its impossible to believe that animal such as a raccoon could not see a difference in the appearance of a water snake to a coral snake or that difference would not represent something to the raccoon. Its also to be considered that not all coral snakes (or venomous snakes) and look alike snakes are banded or heavily patterned. The imitation goes past color and pattern. Venomous snakes and look alike snakes also share copy cat defensive behavior's. These behavior's are the same regardless of the source of the threat (including mammal's) and often involve remaining still and flashing bright warning colors.

None of the animals I mentioned hunt solely in complete darkness. Just like the snakes they are active during periods when there is enough available light to distinguish patterns and color.

Dogs (and other canids) are largely diurnal, but have limited ability to see color. Being active during the day does not mean animals can see color.

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It doesn't matter if an animal sees red, black and yellow banding as bright colors. They can still distinguish the differences in appearance. The colors at the vey least must present a difference in pattern and shading.

I think you're trying to argue for the sake of arguing. Please see my "that said" caveat. As I said, even if an animal cannot distinguish the tricolor pattern, it is a high contrast signal, and would likely appear something like black-and-white banding, which would be an effective aposematic signal. But again, the color itself is not for the benefit of animals that cannot see in color.

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Its impossible to believe that animal such as a raccoon could not see a difference in the appearance of a water snake to a coral snake or that difference would not represent something to the raccoon.

Your biasing your opinions based on your own (literal) views of the world. We can model raccoon vision to actually "see" how conspicuous signals look to them. I do not know that anyone has done this, and my guess would be that they could detect a difference, but I have done enough work with animal vision to know that it's a rookie mistake to assume that what you see is the same as what any animal sees. We have incredibly acute vision. Many animals are not so precise. Not only do we need to take into account whether or not animals see colors and contrasts as we do, but we also need to take into account if they can even see the precise patterns that we do. A whole lot of animals can't.

not surprisingly, w/ a tiny sample size (2) r-runners didnt seem to hesitate pecking @ son corales ... i always wanted to let one at a regalis in an aviary & see if the "esophageal nip" would occur ... rxr ...

edit, thnx 2 the above for their lynx ... i'll see if i can access the articles ... : }

Your biasing your opinions based on your own (literal) views of the world. We can model raccoon vision to actually "see" how conspicuous signals look to them. I do not know that anyone has done this, and my guess would be that they could detect a difference, but I have done enough work with animal vision to know that it's a rookie mistake to assume that what you see is the same as what any animal sees.

Where did I ever say animals see what humans see?

I'm not assuming anything beyond the fact that you probably are some sort of grad student. The generic google style responses and need to validate your credentials are what scream rookie.

I used raccoon's as one example. My comments on raccoon's are not based on assumption but observation and knowledge based reasoning. Raccoon's are highly intelligent problem solver's. They are animals that draw conclusions and make decisions that involved a good deal of visual recognition. They learn quickly. They hunt day and night. Its stands to reason that an animal like this would take a visual clue and learn from it. Based on appearance they know if a prey item is potentially hazardous. Other mammalian snake predators also fall into this category. You can certainly model an animals vison but in this case no one has so its a moot point. And models can be and often are way wrong. Using the available information my statement follows the path of measured logic not assumption. Mammals such as possum's and raccoon's that do often prey on snakes could have an overall limited visual palette but can clearly differentiate commonly seen warning colors. Red , yellow. Visual discrimination tests have shown that the opossum can learn to discriminate black versus white, different colors and can see distant objects. Also it is known that raccoons have much better low-light vision than human beings .

Dogs are not major snake predators and have no need for natural specialized adaptation's visual or otherwise to differentiate between a dangerous snake and a harmless one. Dogs are a poor example.

Regal I would be interested in looking at that paper, I will PM my email.

On the Raccoons - it would be really useful to do a study with them, like the one done on The Neuroethology of Toads, which I think the Toad study itself is of good importance, in covering many basics and the tools and methods used in these types of investigations. To this topic, in looking at it again parts 2 & 3, much of which was quite challenging and requires alot more academic background than I possess, but I like trying. Others here will find it just as compelling and are better familiarized with its concepts.

Perhaps a factor with snakes and predators, mammal predators, in particular, is one of range. A predator interaction with a snake seems to occur within a pretty intimate radius of enabled approach.More so than with rodents, birds, lizards, who are more strident and astute distally to terrestrial approach, generally.

Intrstyng thread, i'd be curious M-man how you design an experiment to determine what another organism can perceive, how does one control for scent/conditioning/etc/ ??

I can only speak to color perception as that is what I work on, and even then, I've not done vision modeling (well, sort of), but essentially, it involves taking retinas of the animals of interest and looking at opsin (light sensitive proteins) expression through the retina. This gives an idea of what colors will be perceived by the retina.

With regard to other stimuli, I'd imagine that you can look at brain activity to determine activation of a particular stimulus.

WSTREPS wrote:

I'm not assuming anything beyond the fact that you probably are some sort of grad student. The generic google style responses and need to validate your credentials are what scream rookie.

Alright, now you are just arguing to argue. All of my research is, is color perception and aposematic signaling. I'd wager I've read more about it in the last week than you have over the course of your entire life. Not to mention what I have researched and published. I'm just going to state unequivocally that I am an expert on the matter.

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I used raccoon's as one example. My comments on raccoon's are not based on assumption but observation and knowledge based reasoning. Raccoon's are highly intelligent problem solver's. They are animals that draw conclusions and make decisions that involved a good deal of visual recognition. They learn quickly. They hunt day and night. Its stands to reason that an animal like this would take a visual clue and learn from it. Based on appearance they know if a prey item is potentially hazardous. Other mammalian snake predators also fall into this category.

All of this is moot. We weren't talking about behavioral learning and avoidance. We were talking about color perception.

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You can certainly model an animals vison but in this case no one has so its a moot point. And models can be and often are way wrong. Using the available information my statement follows the path of measured logic not assumption. Mammals such as possum's and raccoon's that do often prey on snakes could have an overall limited visual palette but can clearly differentiate commonly seen warning colors. Red , yellow. Visual discrimination tests have shown that the opossum can learn to discriminate black versus white, different colors and can see distant objects. Also it is known that raccoons have much better low-light vision than human beings .

No. Just no. Vision modeling is done *all the time.* With respect to Raccoons? Yea, they can't perceive those colors:

Dogs are not major snake predators and have no need for natural specialized adaption's visual or otherwise to differentiate between a dangerous snake and a harmless one. Dogs are a poor example.

You completely miss the point. You argued that because something was diurnal, it should be able to perceive color. I showed that that's not the case. Raccoons and opossums cannot see color, whether or not they hunt during the day. The colors of snakes are not targeted to them. They're targeted to color-perceiving predators like birds. Which are very important snake predators.

M-man, thnx for the info & lynx, i agree with EE, & others, that birds appear to be most terrestrial snakes greatest threats, tho perhaps we miss the cumulative effects of ophidian/mammalian predation ?? It'd be interesting too, how the collared/leopard lizards respond to tricolors as they surely see color like birds? In any case I agree w/ the above, the secret to longevity seems to be to remain unseen, because once discovered, as noted, their various defense strategies seem to be largely ineffectual, although one great exception to all of this are the various sea snakes particularly the yellow belly which is apparently the only vertebrate w/o a known predator! type about paradox ... rxr

No. Just no. Vision modeling is done *all the time.* With respect to Raccoons? Yea, they can't perceive those colors:

Again you must state that you are an expert. Are you or are you not a grad student ? An idea is not proof. Its speculation. And in the world of biology speculation is often very wrong. The study's are filled with uncertainties, assumptions. From the research,

color blindness is not a severe handicap. Hence the S-cone loss was considered a curiosity without much general impact. But of course it raises the question: Why then have most nocturnal mammals retained both cone types and the option to see color? We have no answer yet.

The answer might be because they use it.

To quote the MonarchzMan. "The rookie mistake to assume that what you see is the same as what any animal sees." All the study's are based on how the human eye sees the world. The assumption that the eye of a kinkajou will collect and transmit information to the kinkajous brain the same way it does in a human based on similarities in construction.

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All of this is moot. We weren't talking about behavioral learning and avoidance. We were talking about color perception.

Behavioral learning and avoidance based on color perception. Avoid the brightly colored snake. Not moot. The idea that bright defensive coloration in snakes is predominately to discourage avian attacks and of limited or no value against mammalians because mammal's cant see the colors is a fragile one.

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You completely miss the point. You argued that because something was diurnal, it should be able to perceive color. I showed that that's not the case.

That is incorrect. I never argued that because something was diurnal, it should be able to perceive color. I correctly pointed out that because an animal is considered nocturnal does not mean the ability to see color is of no use. According to you Raccoons and opossums cannot see color, whether or not they hunt during the day. But opossums ( a major snake predator) as the research states have retained both cone types and the option to see color and in other studies have been shown to be able to discern color. Raccoon's are one of only three carnivores that have only one type of cone but again as the research states limited color discrimination is also possible with just one spectral cone type.

Ok again must state that you are an expert. Are you or are you not a grad student ? An idea is not proof. Its speculation. And in the world of biology speculation is often very wrong. The study's are filled with uncertainties, assumptions.

It's a fallacy that graduate students cannot be experts. They are often the most knowledgeable about a subject because they obsess about it for years. The fact of the matter is that I have been research color evolution for 10 years. That makes me an expert irrespective of whether or not I am a graduate student. How much experience working with color evolution do you have?

We're simply dealing with physics. Light travels into the eye, excites particular cells in relation to their physical properties, causes perception of particular colors. There are far fewer assumptions and uncertainties out there for this.

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Behavioral learning and avoidance based on color perception. Avoid the brightly colored snake. Not moot. The idea that bright defensive coloration in snakes is predominately to discourage avian attacks and of limited or no value against mammalians because mammal's cant see the colors is a fragile one.

There are quite literally books and hundreds of papers that say your wrong on this. Avian predators, by and large, have the ability to discern color and perceive these differences. Mammals simply do not. There are some mammals that have color vision, but they are few and far between. You honestly do not know what you're talking about here. Honestly, just stop.

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That is incorrect. I never argued that because something was diurnal, it should be able to perceive color. I correctly pointed out that because an animal is considered nocturnal does not mean the ability to see color is of no use. According to you Raccoons and opossums cannot see color, whether or not they hunt during the day. But opossums ( a major snake predator) as the research states have retained both cone types and the option to see color and in other studies have been shown to be able to discern color. Raccoon's are one of only three carnivores that have only one type of cone but again as the research states limited color discrimination is also possible with just one spectral cone type.

You do not really understand how color vision works. We are trichromats. Birds, tetrachromats. We have three different types of cone receptors, birds four, which allow us to see a wide variety of colors because perception of color from each of these is combined to form one colorful image. Birds see even more than we do as they see in to the ultraviolet spectrum. A single cone receptor effectively means that they cannot see anything but a single shade of color. That's a problem when you're dealing with tricolor snakes. Honestly, just stop.

[quote=] There are far fewer assumptions and uncertainties out there for this. [/quote]

This.^

When people say it is impossible to know, or, that one can only guess because we will never know, about this and other questions of animal perception, its just a matter of the work being done. Or finding and being able to assimilate the work that has already been done.

It was easy to pin down the MonarchzMan. His answers are not the answers that an "expert" would give. They are the answers that a grad student would give. It was obvious.

There are far fewer assumptions and uncertainties out there for this. Really? Is that why the paper's are filled with assumptions and uncertainties. The question remains Why then have most nocturnal mammals retained both cone types and the option to see color? We have no answer yet. MonarchzMan your an expert why don't you contact the author's of the research paper you posted and tell them the answer.

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You do not really understand how color vision works. A single cone receptor effectively means that they cannot see anything but a single shade of color. That's a problem when you're dealing with tricolor snakes. Honestly, just stop.

I do know that in theory that's how its thought to work, Apparently you don't have much more beyond a cookie cutter thinking process. The animal's do not necessarily need to recognize all the colors or see them at full intensity. Maybe for a raccoon with excellent low light vision the ability to see the appearance of what to it looks like faint pale yellow banding might be enough. For a bird the full spectrum is needed to sound the alarm. Assuming that it has to be an all or nothing scenario for all the species that predate on snakes is a process devoid of critical observation and thought.

We are not dealing exclusively with tri colors here in the traditional sense. Its about color based defense strategy's.

As I pointed out earlier some venomous snakes and look alike snakes are basically uncolored and only flash a bright warning when disturbed. Many snakes are dark but have brightly colored undersides. When disturbed they lie still and curl their tails flashing the color. I'm not convinced that this is a great strategy against birds that quickly swoop down and pluck them from the ground, the idea that the bird grabs the snake, the snake flashes its color and the bird drops the snake. Where I live ringneck snakes use this idea. And never once have I seen a bird deterred. Hawks, owls they snatch them right up. Chances are even if dropped the snake wont survive the attack. But against an opossum it might put a stop to things before the damage is done.

There are far fewer assumptions and uncertainties out there for this. Really? Is that why the paper's are filled with assumptions and uncertainties. The question remains Why then have most nocturnal mammals retained both cone types and the option to see color? We have no answer yet. MonarchzMan your an expert why don't you contact the author's of the research paper you posted and tell them the answer.

I do not need to because those papers are actually pretty old and mammalian vision modeling has been done. Guess what? Didn't really change anything. As for why nocturnal mammals retaining cone receptors? Do you understand plesiomorphy and how what likely happened is that cones evolved in an ancestor and were not selected against? I mean, that's not hard to figure out. Presences of cones is not likely a derived feature. Trichromacy and tetrachromacy likely is.

Also noticed that you didn't say how much experience you have with color evolution. So, how much?

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I do know that in theory that's how its thought to work, Apparently you don't have much more beyond a cookie cutter thinking process. The animal's do not necessarily need to recognize all the colors or see them at full intensity. Maybe for a raccoon with excellent low light vision the ability to see the appearance of what to it looks like faint pale yellow banding might be enough. For a bird the full spectrum is needed to sound the alarm. Assuming that it has to be an all or nothing scenario for all the species that predate on snakes is a process devoid of critical observation and thought.

I've explained myself enough. Color is not a deterrent to most mammals. It isn't. Sorry, you're wrong. What could be and what I've said many times before, but you don't seem to recognize is that a high contrast signal would likely be a deterrent. Black, yellow, red would likely appear something similar to white and black. That is a high contrast signal. Why can't you get that?

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As I pointed out earlier some venomous snakes and look alike snakes are basically uncolored and only flash a bright warning when disturbed. Many snakes are dark but have brightly colored undersides. When disturbed they lie still and curl their tails flashing the color. I'm not convinced that this is a great strategy against birds that quickly swoop down and pluck them from the ground, the idea that the bird grabs the snake, the snake flashes its color and the bird drops the snake. Where I live ringneck snakes use this idea. And never once have I seen a bird deterred. Hawks, owls they snatch them right up. Chances are even if dropped the snake wont survive the attack. But against an opossum it might put a stop to things before the damage is done.

Startle displays are thought to startle predators. Yes, that includes birds which have been repeatedly shown to be very neophobic. But color, like I said, is not likely a deterrent to mammals.

I'd also wager you have never seen a bird grab a ringneck snake. Or any conspicuous snake for that matter.

Also, you apparently do not understand how aposematic signaling works. So let's give you a primer. The success of aposematic signaling is predicated on predators attacking prey, having a negative experience, and therefore being deterred from preying upon that species in the future. No where in there does it say that prey need to survive, just that they need to give a sufficiently negative response to elicit avoidance when predators encounter another prey item. The color still is not likely a deterrent to mammalian predators.

Now, before you respond, you offer a lot of conjecture and no evidence. As I said, I'm pretty sure I've read more about aposematic signaling this week than you have ever. How about providing some evidence to back up your assertions? Until then, I'm going to go with the vast majority of the scientific literature in approaching conspicuous coloration in animals.

EE, you are a human pitbull, but lordy it gets old, attitudes like yourself are why so many other thoughtful folks leave the forum, its Scott's "party", act like a grateful guest, articulate your points w/o having to snap & bite ... please ... otherwise check in w/ your avatar ... whats good advice for the goose goes as well for the gander ...

Thanking you in advance .. john gunn

edit M-man, mega thnx for taking the time to further the education of many of us.

I'd also wager you have never seen a bird grab a ringneck snake. Or any conspicuous snake for that matter.

The success of aposematic signaling is predicated on predators attacking prey, having a negative experience, and therefore being deterred from preying upon that species in the future.

You would lose that wager. But for the record what did you base that remark on? Why would you say that?

Here's a little primer for you about how aposematic signaling works. In the example using the ringneck snake the predator does not have a negative experience. Its positive the bird eats the snake then hunts another. Therefore it is not being deterred from preying upon that species in the future. But the snakes do continue to use this display when threatened so clearly it works in some circumstances. Given the nature of the display as described. My point about its use against mammalian predator's is as solid as any other theory.

No Not likely, likely, thought to etc. A lot of hedge betting qualifiers are repeated. There is a lot of conjecture. You keep saying most mammals but we are not talking about most mammals. Most snakes don't use bright colors as a deterrent. We are discussing specific types of mammals and snakes exhibiting specific types of behavior.

Repetition and memorization are rewarded as a sign of intelligence in todays world of academia. I know you have done a lot of reading MonarchzMan. You say it over and over. But what have you done in the field ? Correct me if I'm wrong but didn't you spend time in French Guyana, frogs? Night, rainy day stuff? The area is loaded with the types of mammals and reptiles that exactly apply to the topic of conversation. What did you observe with your own cones and rods ?

You say I don't seem to recognize is that a high contrast signal would likely be a deterrent. But I do, I don't use that as my universal I'm right answer because there are holes in the idea. Possibility's. Observation and behavioral understanding tell me that things are not always what lab studies say they are no matter how many papers make the same claim. If anything can be learned from history its that...We all agree often means we're all wrong.

Here's a little primer for you about how aposematic signaling works. In the example using the ringneck snake the predator does not have a negative experience. Its positive the bird eats the snake then hunts another. Therefore it is not being deterred from preying upon that species in the future. But the snakes do continue to use this display when threatened so clearly it works in some circumstances. Given the nature of the display as described. My point about its use against mammalian predator's is as solid as any other theory.

Do you think a cardinal is aposematic? You do understand that because something has bright colors does not necessarily mean that it is aposematic, right? As I said before, ringneck snakes like do startle displays which are meant to be shocking to give a predator pause long enough for the prey to escape. It does not require learning or a secondary defense. A bullfrog screaming when it's grabbed operates along the same concept. Any number of completely edible insects use startle displays. There is no empirical evidence that I have found that support the idea of Ringneck Snakes being aposematic. That is not to say that they are not, but there is no evidence to support your assertion, and rather, they more typically fit a description of startle display.

Please provide papers to back up your BS. Like I said, you're wrong and you are not helping yourself in proving otherwise.

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No Not likely, likely, thought to etc. A lot of hedge betting qualifiers are repeated. There is a lot of conjecture. You keep saying most mammals but we are not talking about most mammals. Most snakes don't use bright colors as a deterrent. We are discussing specific types of mammals and snakes exhibiting specific types of behavior.

Fine, let's talk about raccoons and opossums. They can't perceive tricolor patterns. I've provided evidence of that. You'v'e only provided conjecture and BS. The fact that you even bring up the qualifiers shows you do not know how science works. We do not use absolutes.

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Repetition and memorization are rewarded as a sign of intelligence in todays world of academia. I know you have done a lot of reading MonarchzMan. You say it over and over. But what have you done in the field ? Correct me if I'm wrong but didn't you spend time in French Guyana, frogs? Night, rainy day stuff? The area is loaded with the types of mammals and reptiles that exactly apply to the topic of conversation. What did you observe with your own cones and rods ?

I have spent over 3 years in the field doing research across the globe. I have plenty of applied knowledge on the subject. Again, what have you done?

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You say I don't seem to recognize is that a high contrast signal would likely be a deterrent. But I do, I don't use that as my universal I'm right answer because there are holes in the idea. Possibility's. Observation and behavioral understanding tell me that things are not always what lab studies say they are no matter how many papers make the same claim. If anything can be learned from history its that...We all agree often means we're all wrong.

Again, we're dealing with simple physics here. Certain cones are excited by certain wavelengths of light. It's not subjective. It doesn't matter if it's done under a forest canopy or under fluorescent lights. You have provided zero evidence to back yourself up, despite my asking multiple times for it. I don't expect you'll do it because you never do. But you're blatantly apparent that you don't understand the material. You should just give it up that you don't know everything about everything and perhaps there are people out there, yes, even graduate students, who are your intellectual superiors on certain subjects.

Ringneck snakes could seem to change form. From one assessed target to 2. From one, to one with an unexpectedly attached paler mass. One dark food appears to have another light one take its place or become different mass than what was at first perceived.

Ringneck snakes could seem to change form. From one assessed target to 2. From one, to one with an unexpectedly attached paler mass. One dark food appears to have another light one take its place or become different mass than what was at first perceived.

I remember reading that mammals take in visual information in a differentformat and rapidity, where a flickering of image is already intrinsic to perception. Bandedness in snakes and its flicker contrast in motion would be an enhancement feature perhaps. Canids I think were the example given.

I find it all very fascinating and it reaches into many focus points. I appreciate every post shared and all of the links and experiences of all you guys helping me understand this topic and become interested in it even more.

-Kelly

The clarification I would like to make to my post is probably only important to me, but as I read this thread again, I caught something in this ones hasty wording that bothers me to be misunderstood. If I am off track with my refinement, at least it would be with what I was actually trying to say..

In saying that flicker contrast in motion would be an enhancement, in relative to a flicker type imaging in mammals (canids was the study focus) it was meant as a neg to canid vision and pos of the bandedness, per the encounter; perhaps creating a clash of scramble - a chaos of resolution.

In reading all of the posts, and opening my mind to many aspects and studies I have been priveleged by other's generousity and energy to share, I must admit I still lean toward contrast in motion and escape creating various responses in predators as a dominant avoidance tactic.

Whether causing a simple delay or a drop or a startle.

But I am still going through the links and realize I have only begun to foray into this topic beyond what before was rudimentary peruse of what is already established, and what was for me ideas born by intuition and intense curiousity.

Thank you for participating, and sharing your research, experiences and most of all your time.

As I said before, ringneck snakes like do startle displays which are meant to be shocking to give a predator pause long enough for the prey to escape.

And what is the point of shock value in the ringnecks startle display. They Flash bright colors. The display is the same as seen in many highly venomous species and the snakes believed to mimic them. And once again when observed it is a display that very likely is used to deter mammalian predators. The ones MonarchzMan insist are colorblind. But not everyone is so convinced. What ? The threads resident expert stated its " simply dealing with physics ". The below statement claims its much more,

Svoke (2011) Concluding that an animal has (or doesn’t have) color vision is a complicated practice because there is a need to examine both the sensory and perception systems. It is, as Roth et al. (2007) state, difficult to actually know how a dichromatic species recognizes any color within their “colour space”.

Perception of Color Vision In the Asian SmallClawed Otter (Aonyx cinerea) Joseph T. Svoke Georgia State University, ZooAtlanta 2011 These conclusions help to support the idea that many mammals are not colorblind, like previously thought.

Originally, it was thought that most mammals are colorblind (Jacobs 1981; Padgham & Saunders 1975; Walls 1942). In recent years, this idea has been shown to be incorrect.

Conflicting results have been reported for the domestic cat with some reporting they are trichromatic (Ringo et al. 1977), whereas others say that there is no active mechanism (Loop et al. 1985).

the mink (Dubin & Turner 1977) and the ferret (Calderone & Jacobs 2003) were shown to have the physiological mechanisms present for color vision.

Trichromatic vision is also suggested to exist in marsupials. Possums . (Arrese et al. 2002) being one that reported this finding .

And what is the point of shock value in the ringnecks startle display. They Flash bright colors. The display is the same as seen in many highly venomous species and the snakes believed to mimic them.

Startle displays are, now I hope you can follow my logic because it's apparently difficult for you, are meant to startle. Birds can be highly neophobic, and thus a startle display can give them enough pause for a snake to escape. This is likely a target for birds as they are sensitive to long wavelengths (reds, oranges, yellows), which you'll note, is what the ventral colors of ringnecks are.

What species? And where is evidence of mimicry? As I said, provide evidence.

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And once again when observed it is a display that very likely is used to deter mammalian predators. The ones MonarchzMan insist are colorblind. But not everyone is so convinced. What ? The threads resident expert stated its " simply dealing with physics ".

You can't have it both ways. You can't say that "there is a lot of uncertainty in these things" and then post papers claiming the opposite. You also do not understand the argument. Determining what colors animals can perceive is simple physics. This is something we do all the time: modeling vision in animals, which helps inform our research.

And again, you completely ignore my call for evidence. Please provide proof that these displays are deterrents to mammalian predators. You simple insistence does not constitute proof.

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The below statement claims its much more,

Svoke (2011) Concluding that an animal has (or doesn’t have) color vision is a complicated practice because there is a need to examine both the sensory and perception systems. It is, as Roth et al. (2007) state, difficult to actually know how a dichromatic species recognizes any color within their “colour space”.

Perception of Color Vision In the Asian SmallClawed Otter (Aonyx cinerea) Joseph T. Svoke Georgia State University, ZooAtlanta 2011 These conclusions help to support the idea that many mammals are not colorblind, like previously thought.

The Svoke study is a thesis and has not been published in a peer-reviewed journal. Theses, while informative, need to be taken with a grain of salt. To be honest, I'm surprised that this particular thesis was accepted because it has zero statistical analyses to actually back up their conclusions. If we take it to be true, we can actually determine that the otters can see some blue/green, which is pretty consistent with findings of most dichromatic mammals. They did, however, have issue with differentiating red from gray, thereby showing that they cannot discern typical warning coloration.

They also say nothing about Small-Clawed Otters being important predators of tricolor snakes.

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Originally, it was thought that most mammals are colorblind (Jacobs 1981; Padgham & Saunders 1975; Walls 1942). In recent years, this idea has been shown to be incorrect.

Conflicting results have been reported for the domestic cat with some reporting they are trichromatic (Ringo et al. 1977), whereas others say that there is no active mechanism (Loop et al. 1985).

the mink (Dubin & Turner 1977) and the ferret (Calderone & Jacobs 2003) were shown to have the physiological mechanisms present for color vision.

Trichromatic vision is also suggested to exist in marsupials. Possums . (Arrese et al. 2002) being one that reported this finding.

You literally only looked at this questionable thesis for your support. It's almost as if you don't understand science to see the blatant issues with this thesis. None of these mammals discussed are discussed in the context of being important predators of tricolor snakes. And I also never said that no mammals have trichromacy.

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All the animals listed in those study's regularly predate on snakes.

Grizzly Bears eat fish, but I'm not about to use them as a model of coral reef fish predation. None, not one, of the studies that this thesis cite (to be clear, it's this thesis, not you) provide evidence that mammals can perceive the color differences in tricolor snakes, nor that any possible avoidance is due to color and not contrast (as I suggest).

I'm also waiting on you to say your expertise on color vision and aposematic signaling. I've noticed that you have been ignoring that question.

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